Of course, the above system does not refer to sound reinforcement (although sound reinforcement is also included), because from more than a hundred years ago when Edison invented the phonograph to the rapid development of sound technology today, recording and reproducing sound that transcends time and space barriers has always been the primary task of sound systems. Therefore, sound systems can be divided into two types: sound production (recording) and playback.

It should be said that there is also a stage of sound propagation between the production and playback of sound. The propagation of sound includes the circulation of sound records on certain carriers (such as magnetic tapes or CD records) or the transmission of radio waves through broadcasting. However, this does not belong to the scope of sound systems, as the former is not a system composed of electronic devices, and the latter is not an audio signal system.

Whether it is sound production or playback, there is another important task, which is sound processing. Because sound production and playback cannot mechanically reproduce the original sound, it is not only necessary to eliminate the drawbacks of the original sound, but also to beautify the sound quality according to certain aesthetic requirements, and even to create sounds that were not originally present, which is also the responsibility of the sound system.

According to different requirements and tasks, as well as different occasions, there are different sound systems that can be classified from different perspectives, including professional sound systems and home sound systems on a large scale. Professional audio systems can be divided into production systems and playback systems. Production systems include music recording production systems and film and television recording production systems. Regardless of which production system is sometimes divided into pre production and post production systems, as well as broadcasting production (real-time or recording) systems; The playback system includes sound reinforcement systems for cinemas, sports venues, venues, conference halls (rooms), song and dance halls, disco halls, karaoke sound systems, etc. Home audio systems can be divided into music playback systems and AV playback systems; AV playback systems include home theater surround systems and karaoke systems.